I had a pair of cheap speakers (40-50 dollars, i don´t remember) and one headphones with much better quality ,the Sony NWZ-WH303 (I´m not saying that they´re awesome and the best but are better than the speakers)
Should I start to produce more with the headphones ? How good are they?
Ahhh man, this is one of those questions everyone starting out has. I went through it myself and did a lot of research so I'll attempt to shed some light 
So, to make sure I understand your question, you're asking if you should produce on your headphones as opposed to speakers since your headphones are higher quality, and if so, what might you be missing out on by not using monitor speakers?
So, the headphones you have are indeed pretty decent, though they are NOT what one would call studio headphones. They seem like they're made for recreational use. The difference is that studio headphones have a "flat" frequency response and are very honest, whereas recreational headphones boost the bass and treble like crazy to make it seem like everything sounds better on them However, this is more of an issue for MIXING, not necessarily when you're first starting to produce and just playing around with sounds and building your track. Mixing and producing DO go hand in hand however, so you might want to look into a pair of studio headphones.
There are 2 main types of studio headphones - closed back and open back. Closed back are like what you have, and open back are, ...um... open on the outside haha. If you are in a quiet home studio open headphones will sound better, but if you're in noisy environments or produce on the train or on the bus or in coffee shops go wth closed back headphones.
The most popular closed back cans people recommend are Audio Technica ATHm50x. They're around $160, but you can def get cheaper headphones, I'll put a list of resources for you to research (based on your budget of course) at the bottom.
Ok, so your cheap speakers are not going to do you many favors when producing or mixing or anything. You should keep them though, because they say to get the best mix possible you should be auditioning your tracks all over the place - cheap speakers, cheap earbuds, car stereo, etc etc. Basically get as many different "looks" at your track as you can on different systems.
For proper studio monitor speakers, it's kind of like studio headphones. There are a ton to choose from. As people in this thread have mentioned, with monitor speakers you'll feel and hear the low-end of your music more. If you forced me to choose yes or no, then YES, it IS better to produce and mix on monitor speakers as opposed to headphones. But again, there are many degrees of truth here. Many famous producers have had great results using really crappy gear, and not even having monitor speakers for instance.
So, to recap & conclude - you can absolutely produce w the headphones you have, because why not, people have had to make do w worse 
Is it ideal? No. For a more ideal setup, find yourself some studio headphones (open or closed back depending on ur situation). Your existing cheap speakers should be used to occasionally listen to your mix for reference, but probably won't make the best monitors. If you can afford it, you should buy some monitors.
Educate yourself on this stuff and you should get an idea for what to buy. Here is some recommended reading, I found these guides to be some of the most well informed (and they're beginner friendly):
closed backs help simulate and isolated environment inside your head. typified use is in more noisy environments or when you mic drums or loud ass band mates who won't STFU.
Open backs are typified as the mixing headphone of choice; they are the studio grade headphones that you make mix decisions on.
The difference between utilizing those two comes with understanding and relevance between the two systems (eventually three systems when you involve the studio monitors or any other number of alterations due to studio headphones and speakers).
Get open backs, and get studio speakers.
If you have to choose one, getting a really nice pair of headphones (in the 300 buck range will last you a while;my preference is beyerdynamic dt 990), and they are the really nice entry level to professional mixing options.
every thing is colored for a specific purpose, so to say that studio monitors are "flat" would defeat the purpose of having different brands; they'd all have the same functionality if they were all of the same in operation.
The best way to go is to pick a budget save up, explore and listen to what you want to get familiar with for thousands of hours when you produce.
The only real difference you need to understand is the utilization of the tools that best optimizes performance for a specific reference point.
On top of open back headphones and studio monitors, i have audio technica x40(i read they were better than the x50 in terms of quality and performance) closed back, and i use them as often as i can when i mix and master. I tend to use them as a way to check feeling and what a decent pair of consumer speakers would sound like (they do an ok job in mixing, but they're just not as accurate as open backs)
